A conventional baby stroller generally has a tray positioned across a child seat for use by a child seated on the child seat. The tray has two tray arms pivotably connected to a stroller frame to be folded and unfolded along with folding and unfolding of the stroller frame. A tolerance connection between the tray arms and the stroller frame is required to perform the folding and unfolding operations, which results in unsteady engagement therebetween, thus undesired swaying of the tray occurs during use.